Oil in air filter/air filter housing

Oil in air filter/air filter housing

I'm in the process of R&R my plugs and wires and decided attack the TB. When I popped off the cover to the air housing I found a corner of the airfilter(spongy part) soaked with oil as well as some caked on oil on the inside of the housing. Also the pcv hose that connects the back of the housing to the valve cover had oil in it to.

It sounds to me like you need to check your PCV valve. The PCV valve is suppose to prevent this type of oil blowback that you described, and I believe is suppose to only work one direction to prevent this type of thing. It is easy to check. Remove the valve, and shake it. It should rattle. If you still are not sure, just buy another one, they only cost a few bucks, and are quick and easy to replace. Prior to installing, clean up the oil that you saw, replace the valve and check for future blowback in the future.

The oil in the driver's side crankcase ventilation inlet tube and on the air filter element is normal. It's from normal crankcase pressure blow back. The V10 CCV (crankcase ventilation system) uses an FOF (fixed orifice fitting) in lieu of a PCV. Take a long hard peek at the other valve cover (passenger side). There is an elbow on top of that valve cover with a vacuum tube attached to it. The other end of this tube goes to the FOF on the intake manifold. Wouldn't hurt to remove it and clean it. It has a calibrated hole (orifice) of .1 inch. About 2.6 mm, I think. Gee, the dealer didn't tell you this?

When I had this problem on my 94, my dealer was stumped.I had it in a couple of times for different checks until I just gave up on them.During my own tests and checks I found that if I drove nice around town and took it easy on the highway then I could go the full duration between service checks without any oil on the filter.But... as soon as I opened her up and drove her hard, I would get oil up into the air cleaner after just one trip. I just assumed it had to do with crankcase pressure at higher rpms and have never given it a second thought. Once I switched to a K&N, I wasn't too worried about oil on the filter anyway.